It is known that 1H-pyrazoloazole couplers, such as 1H-pyrazolo[1,5-b]-1,2,4-triazole compounds and 1H-pyrazolo[3,2-c]-1,2,4-triazole compounds, are magenta couplers that give excellent hue, as respectively described in U.S. Pat. Nos. 4,540,654 and 3,725,067. 1H-pyrazolo[1,5-c]-tetrazole couplers, 1H-imidazo[1,2b]pyrazole couplers, and 1H-pyrazolo[1,5-a]benzimidazole couplers are also described in JP-A ("JP-A" means unexamined published Japanese patent application) Nos. 33552/1985 and 162548/1984 and U.S. Pat. No. 3,061,432, respectively. 1H-pyrazoloazole compounds are known as cyan couplers in JP-A No. 264753/1988.
Processes for synthesizing these pyrazoloazole compounds are described, for example, in JP-A Nos. 190779/1985, 197688/1985, 215687/1985, 145163/1986, 18780/1986, and 249969/1986.
In these processes for synthesizing pyrazoloazole compounds, various compounds are reported as synthetic intermediates, and among these, 5-amino-4-halogeno-1H-pyrazole compounds are important.
For example, JP-A Nos. 239272/1988 and 6274/1989 describe 5-amino-4-halogeno-1H-pyrazoles as starting material that will lead to 1H-pyrazolo[1,5-b]-1,2,4-triazoles, and JP-A Nos. 249969/1986, 10068/1987, and 252773/1987 describe 5-amino-4-halogeno-1H-pyrazoles as starting material that will lead to 1H-pyrazolo[3,2-c]-1,2,4-triazoles. Thus, 5-amino-4-halogeno-1H-pyrazoles are quite useful synthetic intermediates in the synthesis of pyrazolotriazole compounds, and all the processes for the synthesis thereof involve halogenation of 5-amino-1H-pyrazoles. Major examples are: ##STR3##
Although processes for the synthesis of 5-amino-1H-pyrazoles as starting materials are described, for example, in the Journal of American Chemical Society, page 144 (1945), U.S. Pat. No. 2,987,523, JP-B ("JP-B" means examined Japanese patent publication) No. 26082/1970, the Journal of Heterocyclic Chemistry, Vol. 11, page 423 (1974), and JP-A Nos. 65245/1986 and 236768/1986, they are accompanied by such problems as that many steps are involved and starting materials are expensive and not readily available. Therefore, as long as these starting materials are used, similar problems are involved in the synthesis of 5-amino-4-halogeno-1H-pyrazoles, which are desired to be solved.